Saturday, May 26, 2012

Tropical Storm Beryl (2012)

Storm Active: May 25-30

On May 21, a low pressure system developed near the eastern coast of the Yucatan Peninsula. From there, it slowly moved northeast, and accumulated some more significant cloud cover on May 23. Initially, conditions were very hostile for development, but as the low tracked farther northeast, the upper-level winds slowly abated, and the circulation became better organized. On May 24, the system moved over Cuba, bringing some rainfall to it and neighboring Caribbean islands. Later that day, the western edge of the system passed over the Florida keys.

The center of the low became much better defined late that night and into May 25, and the convection increased markedly, though mainly in the northern and eastern quadrants. The system continued to move northeast, but its motion slowed as it encountered strong ridges of high pressure to its north and east. Late that evening, thunderstorm activity flared up near the center, and the low was upgraded to a tropical cyclone. However, due to its proximity to an upper-level low and its relatively broad circulation, it was designated Subtropical Storm Beryl.

Beryl's motion reversed early on May 26 as it adopted a west-southwest track. Its convection remained limited, as dry air was invading the center from the southeast, but the cyclone became more symmetrical in appearance as it moved toward the U.S. coastline. Over the following day, Beryl became slightly more organized, and experienced modest intensification late that night. The system veered more to the west early on May 27 and accelerated somewhat. More powerful rain bands developed that same morning, but the center remained broad as the cyclone approached the Florida coastline.

Later that day, the windfield contracted and intense thunderstorm activity appeared near the center of circulation, meriting a reclassification of Beryl as a fully tropical cyclone. Despite its proximity to land, Beryl was rapidly strengthening during the afternoon of May 27. It nearly reached hurricane strength, achieving its peak intensity of 70 mph winds and a minimum central pressure of 992 mb late that night before making landfall near Jacksonville Beach, Florida very early on May 28.

The convection quickly deteriorated over land that morning, but the circulation remained intact, and the rainbands near the coastline still caused heavy rain, as they tapped into Atlantic moisture. The winds fell quickly, however, and Beryl was downgraded to a tropical depression by late morning. Over the following day, Tropical Depression Beryl tracked further inland, crossing into Georgia, and then slowed in forward speed as the ridge to the north weakened. Soon, the typical steering patten emerged, and Beryl turned to the northeast.

On May 29, the convection associated with the tropical depression began to be entangled with a front to the north. As the depression crossed over land into South Carolina, all of the remaining rain bands were displaced significantly poleward. Despite this, Beryl's circulation deepened, but this was probably due to the beginning of extratropical transition. During the afternoon of May 30, as Beryl regained tropical storm intensity near the North Carolina coast, it became post-tropical. Soon after, it was absorbed by a front.

Beryl was the strongest preseason cyclone since 1972, and, since it was the second named storm to form before the start of the official hurricane season (begins June 1), 2012 was only the third Atlantic hurricane season in history to have two preseason storms, after 1887 and 1908.

Beryl near peak intensity, just before making landfall in Florida. Beryl was one of the strongest U.S. landfalling off-season storms in history.

Track of Beryl.

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